This invention relates to a wound treatment device and, in particular, to a wound treatment device having a substantial portion of a wound cover that is in non-contact with a wound and capable of delivering heat to the wound. More particularly, the wound treatment device includes a flexion joint that maximizes the ability of the wound treatment device to adapt to the contours and movements of a human body.
A novel mode of wound treatment is disclosed in detail in published PCT Applications WO 94/00090 and WO 96/15745, both owned in common with this application. This new treatment employs a non-contact wound treatment device that covers a wound, forming a treatment volume about and over the wound. An embodiment of such a wound treatment device may be characterized in having a plurality of parts, three of which are useful for the purpose of description. These three parts are an attachment portion, a wound treatment portion, and a transition portion. Each portion serves a respective function.
The attachment portion connects and retains the wound treatment device on the skin of a person. The wound treatment portion typically includes a standoff that rises above the person""s skin surface, and a wound cover that spans an open portion of the standoff. Together, the standoff and wound cover define a wound treatment volume and a wound treatment area onto which the wound treatment volume is projected.
The transition portion connects the attachment portion to the wound treatment portion. An important function of the transition portion is to adapt the wound treatment device to the contour of the portion of a person""s body where the device is mounted and to movements of the person""s body that deform the wound treatment device in situ. In this regard, an important function of the transition portion is the accommodation of patient motion by the compliance of the transition portion.
Achievement of this important function of the transition portion is challenged by the need to maintain the orientation of the wound cover in the wound treatment portionxe2x80x94both in aspect and locationxe2x80x94with respect to the wound being treated. The orientation of the wound cover is difficult to maintain when the wound treatment device is mounted on a highly curved part of a body. While the wound treatment devices disclosed in the referenced PCT applications exhibit excellent adaptability in a surface that is parallel to the surface of the body portion where the wound treatment device is mounted, there is impairment of adaptability and disturbance of the orientation of the wound cover due to limited flexibility in the direction of a Z axis that is perpendicular to the surfaces. If the transition portion is substantially perpendicular to the attachment portion, it may buckle in response to body motion or contour and collapse the standoff in the wound treatment portion. The collapse of the standoff of course alters the orientation of the wound cover with respect to the wound, possibly reducing the effectiveness of the wound treatment device.
Z axis conformability is especially important for a wound treatment device used on a portion of a person""s lower leg. The lower leg has a very tight radius of curvature. Therefore, when a three-dimensional wound treatment device is curved around a lower leg, substantial stress results that may result in deformation of the shape of the wound treatment device, in some cases even causing the wound cover to contact the wound.
The overall flexibility of a wound treatment device is enhanced by an invention based upon the inventors"" critical realization that provision of a membrane in the transition portion that connects the wound treatment portion to the attachment portion accommodates patient motion and contour by paying out stored material to flex the wound treatment device in all dimensions of the volume that the wound treatment device occupies.
In this invention, the membrane connects the wound treatment portion to the attachment portion, extending between the wound cover and the attachment portion, around the outside of an outer periphery of the standoff in the wound treatment portion. Under the standoff, the membrane attaches to the attachment portion between inner and outer peripheries of the attachment portion.
Preferably, the inner periphery of the attachment portion along which the membrane is attached is limited to being contained within the outer periphery of the standoff. This permits reduction of the size of the attachment portion, minimizing the total xe2x80x9cfoot printxe2x80x9d of the wound treatment device. A smaller footprint is generally considered to be advantageous particularly when attaching the wound treatment device to a highly curved part of a person""s body, such as the surface of a lower leg.
The membrane, its connection of the wound treatment portion with the attachment portion, and its attachment to the attachment portion along an inner periphery of the attachment portion provide a flexion joint, or a double hinge that maximizes the adaptability of the wound treatment device and maintains the orientation of the wound cover over greater ranges of body curvature and movement than previously obtainable.
It is, accordingly, an objective of this invention to provide a flexible, non-contact wound treatment device that adapts to body curvature and motion.
Another objective is the provision of a non-contact wound treatment device having a wound treatment portion, an attachment portion, and a transition portion with a membrane connecting the wound treatment and attachment portions.
It is a related objective in this latter regard to provide a flexion joint between the wound treatment and attachment portions in the form of a membrane in the transition portion.
A significant advantage of the invention is the potential reduction in size of the attachment portion, providing a smaller footprint of the wound treatment device.